Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
BACKGROUND OF THE INVENTION
The ~present invention relates to catheters, and more
particularly to valve assemblies for catheters.
An assortment of catheters, such as Foley catheters
and endotracheal tubes, have been proposed for use in patients.
Many of the catheters include an inflatable balloon which is used
for various purposes, such as sealing a passage in the patient
or retaining the catheter in place in the patient. The cathe-
ters normally have a valve and a lumen communicating between the
valve and the balloon to permit inflation and deflation of the
balloon.
Although a number of valve structures have been uti-
lized in prior catheters, most of the valves are of relatively
complicated construction requiring an excessive number of parts
thus rendering the valve more costly than necessary. The cathe-
ters are normally considered a disposable item, and are discarded
after a single use. Accordingly, it is desirable to provide the
catheters at a minimal cost to the patient.
SUMMARY OF THE INVENTION
-
A principal feature of the present invention is the
provision of a catheter with an improved valve assembly of
simplified construction and reduced cost.
The catheter of the present invention comprises, a con-
duit having a lumen, and a valve assembly for the lumen. The
valve assembly has a housing having a cavity communicating with
the lumen, a port, and a seat extending peripherally around the
port. The valve assembly also has a valve element of elastic
material received in the cavity and having a first portion defin-
ing a surface for sealingly engaging against the seat. The
valve element has a second portion connected to the housing at a
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location such that it stretches responsive to contact against
the first portion through the port.
A feature of the present invention is that the second
portion of the valve element biases the sealing surface of the
first portion against the seat to cause sealing engagement between
the sealing surface and the seat and close the valve.
Another feature of the invention is that the second
portion stretches and permits movement of the first portion away
from the seat to permit passage of fluid between the sealing sur-
face and the seat.
Thus, a feature of the invention is that the valveassembly provides a reliable closure for the catheter lumen which
may be readily opened by contacting the first portion with the
tip of a syringe through the port.
Still another feature of the invention is that the
valve assembly may be constructed from few noncostly parts, thus
resulting in a relatively inexpensive structure of the valve
assembly for the catheter.
Further features will become more fully apparent in
the following description of the embodiments of this invention
and from the appended claims.
DESCRIPTION OF THE DRAWINGS
In the drawings:
Fig. 1 is a fragmentary elevational view, partly broken
away, of a catheter including a valve assembly of the present
invention;
Fig. 2 is a sectional view of the valve assembly of the
present invention;
Fig. 3 is an upper plan view, taken partly in section,
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of a valve element for the valve assembly of Fig. 2;
Fig. 4 is a fragmentary elevational view of an annular
member of the valve assembly housing which defines a valve seat;
and
Fig. 5 is a sectional view illustrating use of the valve
assembly of Fig. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to Fig. l, there is shown a catheter gen-
erally designated 10 having an elongated shaft 12 and a valve
assembly 18. Although for convenience the valve assembly of the
invention will be described in connection with a urinary cathe-
ter, it will be understood that the valve assembly may be uti-
lized in conjunction with any other suitable catheter, such as
an endotracheal tube or embolectomy catheter. The catheter 10
has an inflatable balloon 14, and a side arm 16 extending out-
wardly from the shaft 12, with the valve assembly 18 being
secured to an outer end 17 of the side arm 16. The catheter has
an inflation lumen 20 extending through the side arm 16 and a
wall of the catheter shaft 12 in order to establish communica-
tion between the valve assembly 18 and the balloon 14 for infla-
tion and deflation thereof. The catheter 10 also has one or
more drainage eyes 22 adjacent a distal end 24 of the catheter
10, and a main or drainage lumen 26 communicating with the drain-
age eyes 22 and extending through the shaft 12 to a proximal end
28 of the catheter 10.
In use, the distal end 24 of the catheter 10 is passed
through the patient's urethra until the drainage eyes 22 and the
balloon 14 are located in the patient's bladder, with the proxi-
mal end 28 of the catheter 10 located outside the patient's body.
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The balloon 14 is inflated through the valve assembly 18 and the
inflation lumen 20 in order to retain the catheter in place in
the patient. During catheterization, urine drains through the
drainage eyes 22, the main lumen 26, and a drainage tube (not
shown) to a bag (not shown) for collection of urine therein.
Referring now to Figs. 2-4, the valve assembly 18 has
a housing 30 defining a cavity 32, and a valve element 34 of
elastic material received in the cavity 32. The housing 30 has
an outer member 36 having an outer or proximal wall 38 and a cyl-
indrical side wall 40 extending from edges of the outer wall 38.
The outer member 36 of the housing 30 also has an annular member
42 extending from the outer wall 38 into the cavity 32, with the
annular member 42 defining a tapered port 44. The annular member
42 has a tapered portion 46 defining an annular valve seat 48 at
an inner end of the annular member 42 extending peripherally
around the port 44.
The housing 30 also has an inner member 50 having a
cylindrical side wall 52 snugly received within the side wall 40
of the outer member 36. The inner member 50 has an inner or dis-
tal wall 54 defining an inner portion of the cavity 32, and a
tubular section 56 extending distally from the inner wall 54.
With reference to Figs. 1 and 2, the tubular section 56 is
received in the outer end 17 of the catheter side arm 16 in order
to establish communication between the cavity 32 of the valve
assembly 18 and the inflation lumen 20 of the catheter 10.
With reference to Figs. 2-4, the valve element 34 has
a generally cylindrical first portion 58 having a sealing surface
60 on its inner face defined by an annular groove 62 which
receives the tapered valve seat 48. The first portion 58 has a
transverse slot 64 intermediate the sealing surface 60 for a
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purpose which will be described below. The valve element 34
also has a second portion 66 having an annular outwardly directed
flange 68f and a relatively thin annular strap section 72 extend-
ing between and connecting the flange 68 and first portion 58.
The valve element 34 has one or more openings 70 which extend
through the valve element at a location remote the surface of
the first valve element portion 58 bounded by the sealing surface
60. In the particular embodiment shown, the openings 70 extend
through the strap section 72, although it will become apparent
that the openings (70') may extend through side portions of the
first valve element portion 58 outside the groove 62, as illus-
trated in Fig. 2, if desired. As shown in Fig. 2, the flange 68
has a width approximately equal to the distance between the annu-
lar member 42 and the side wall 40 of the outer member 36. The
valve element flange 68 is connected to the housing at the outer
end of the cavity 32 between the outer wall 38 of the outer hous- ¦
ing member 36 and an outer end 53 of the inner member side wall
52. In this manner, the valve element 34 is secured in the hous-
ing cavity 32 with the first portion 58 of the valve element
located over the inner end of the housing annular member 42. The
strap section 72 of the valve element has a suitable length such
that the valve seat 48 is received in the groove 62 with the seat
engaging against the sealing surface 60.
In use, with reference to Fig. 2, the strap section 72
of the valve element 34 biases the first portion 58 and asso-
ciated sealing surface 60 against the valve seat 48, such that
the valve seat sealingly engages against the sealing surface 60.
Thus, in its normal configuration, the valve element 34 closes
the valve assembly 18 and prevents passage of fluid between the
port 44 and cavity 32.
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With reference to Figs. 1 and 4, when it is desired to
inflate the balloon 14 of the catheter 10, the tip T of a syr-
inge S may be inserted into the housing port 44 until the tip T
engages against the valve element first portion 58 and moves the
sealing surface 60 away from the valve seat 48. Next the syr-
inge S is pumped, and fluid passes through the tip T and through
the slot 64 of the first portion 58 which prevents obstruction
of fluid passing from the syringe tip. The fluid then passes
through the openings 70 of the strap section 72 into the remain-
ing portion of the cavity 32, after which the fluid passes
- through the inflation lumen 20 to the balloon 14 for inflation
thereof. The syringe is thus pumped until the balloon is prop-
erly inflated, and the syringe is then removed from the valve
assembly 18. In turn, the strap section 72 again biases the
first portion 58 and-sealing surface 60 into sealing engagement
against the valve seat 48 to close the valve and prevent passage
of fluid from the balloon through the valve assembly 18. In
this configuration, back pressure from the balloon 14 causes the
; valve element first portion 58 and associated sealing surface 60
to tightly engage against the valve seat 48 in order to obtain
an excellent seal between the valve element 34 and valve seat 48
during catheterization.
After catheteriæation has been completed, the syringe
tip T is again inserted through the port 44 to stretch the strap
section 72 and move the valve element first portion 58 away from
the valve seat 48. The syringe may then be utilized to aspirate
the fluid from the balloon through the inflation lumen 20 and
the valve assembly 18 into the syringe. Alternatively, any suit-
able instrument may be passed through the port 44 in order to
move the valve element first portion 58 away from the valve seat
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48, such that the instrument opens the valve and releases the
fluid from the balloon.
Thus, in accordance with the present invention, the
valve assembly may be constructed from few and relatively inex-
pensive parts in order to reduce the cost of the disposable cath-
eter to the hospital and patient. In addition, the valve assem-
bly functions in an excellent manner to permit inflation and
deflation of the balloon. In a preferred form, the valve ele-
ment 34 may be constructed from any suitable elastic material,
such as rubber. The inner member 50 and outer member 36 of the
housing may be molded from a suitable plastic, such as polyvinyl-
chloride or polyethylene.
The foregoing detailed description is given for clear-
ness of understanding only, and no unnecessary limitations should
be understood therefrom, as modifications will be obvious to
those skilled in the art.
